Getting Started

1. Install MongoDB.

Just follow the instructions for your specific device OS from this link. I currently use Mac OS X. My notes reflect usage of environment. YMMV.

2. Run MongoDB.

Verify that your install is correct by running the MongoDB server on your local machine as described here. Make sure that the local PATH is set to include the location of the mongod and mongo binaries from this distribution.

mkdir -p /data/mydb        --> identify local db location
chmod u=rwx /data/mydb     --> give user read/write access to db

mongod --dbpath /data/mydb --> run the Mongo daemon

At this point, the mongodb database server (daemon) is running.

3. Run the Mongo Console.

Use the mongo utility to connect to the mongodb server and open a shell for interactions.

mongo
MongoDB shell version: 2.6.4
connecting to: test
>

You should see the above output, followed by a prompt for commands.

The mongo shell is a powerful, interactive interface for viewing, querying and maintaining all MongoDB databases on the connected server. Check this page for a comprehensive reference to the mongo shell commands.

Explore available menu options with the 'help' command.

> help
    db.help()                    help on db methods
    db.mycoll.help()             help on collection methods
    sh.help()                    sharding helpers
    rs.help()                    replica set helpers
    help admin                   administrative help
    help connect                 connecting to a db help
    help keys                    key shortcuts
    help misc                    misc things to know
    help mr                      mapreduce display on shell
    ....

    exit                         quit the mongo shell
>

You can quit the shell at any time with exit.

4. Quick Commands

For convenience, here are the most frequently used shell commands.

• db = show currently active db
• show databases = show all (non-empty) dbs on this server
• show collectios = show all collections in current db
• use mydb = make 'mydb' the current (active) db
• db.help() = list all methods that can be called on db
• db.createCollection('myColl') = create the 'myColl' collection on current db
• db.showCollections() = show all collections in current db
• db.dropDatabase() = delete the db

The following commands are used on a specific collection (where myColl should be replaced by the appropriate collection that you are running these commands on)

• db.myColl.help() = list all methods that can be called on this collection
• db.myColl.drop() = delete this collection
• db.myColl.dropIndexes() = delete a specific index on this collection
• db.myColl.getDB() = get the db object associated with this collection

This is a list of frequently used commands for basic CRUD (create, read, update, delete) operations that most applications require.

• db.myColl.count() = returns number of documents in this collection
• db.myColl.insert(obj) = inserts the specified document (obj) in this collection (, creating the collection if non-existent)
• db.findOne(query) = find one (the first) document matching the query.
• db.myColl.find(query) = find all matching documents in the collection (returns cursor, which is transient. To get data as well, use .find().fetch() in Meteor only)
• db.myColl.update(query, object[.., upsert_flag, multi_flag]) = updates the document(s) selected by the query with the data in the object. If upsert_flag is true, this will insert the document if it did not exist a priori. If multi_flag is true, it updates all matching documents for query (not just the first match).
• db.myColl.remove(query) = remove all documents matching the query. Note that if query is an empty document ({}), this removes all documents in collection. This is different from dropping the collection since this approach retains indexes.

Notes